250 THE CORAL LANDS OF THE PACIFIC. 



as for the making of dishes, spoons, fish-hooks, knives, and 

 a variety of implements ; consequently in islands where it was 

 not indigenous, they were most anxious to obtain it, and with 

 that view made repeated attempts to introduce it into their 

 own lakes, by carefully transporting the young shells attached 

 to pieces of rock from one island to another, keeping them all 

 the time in pure sea-water ; but they never succeeded. More- 

 over, there is 110 tradition of the pearl-oyster having once 

 existed in a place, and having become extinct ; consequently 

 there is some condition necessary to its growth with which we 

 are unacquainted. 



There is no variety in the species, but very much difference 

 in the size and thickness to which it attains in divers localities, 

 as also in the production of pearls of value. For some of these 

 peculiarities there is a way of accounting. The pearl-oyster of 

 the Pacific dislikes sand, and will not live upon it, or grow to 

 its full size in its immediate vicinity that is to say, in a tide- 

 wave, or where the sand pollutes the water. In still lagoons, 

 where the sand lies at a depth and is never moved, the pearl- 

 shell grows well on the rocks which rise out of it. But this 

 fish most delights in the great caves and hollows of the clean- 

 growing coral, where the waters are limpid, and altogether free 

 from such extraneous atoms as might irritate and annoy it. In 

 such situations it grows to a great size (sometimes as much as 

 eighteen inches in diameter). These huge bivalves frequently 

 attach themselves to the roofs of caverns, sometimes a dozen 

 being linked together by the strong fibrous threads whereby 

 they make themselves fast : a rich prize for the diver, who is 

 obliged to separate them with his knife, and from their ex- 

 ceeding weight to make more than one plunge before securing 

 the whole of the congeries. As a general rule, in well-fed and 

 clean-grown fish such as these, pearls are seldom to be met 



